The microswitches are rated for 50-80M clicks nowadays.

Though in practical sense, they all still will get double click issue under 1-2 years, which unlikely to exceed even 1M of clicks.

I came across a theory before that it’s because it’s working at under rated voltage range by mouse makers to save power especially on wireless mouse. As a result the oxidation process happened worse than it’s designed.

Nowadays OMRON losing the throne position to other Tongsan switch makers like KAILH or TTC.